20 Best API Testing Tools: REST & SOAP Web Services

An API or Application programming interface is a collection of software functions and procedures through which other software applications can be accessed or executed. In API Testing you use software to send calls to the API, get output and log the system’s response. For Agile development, Api Testing becomes important as shorter development cycles put more pressure on automated testing.

Here is a list of top Web Services Testing Tools

1) SOAtest

Parasoft SOAtest is the industry-leading API testing solution, which simplifies the process of creating automated end-to-end test scenarios across multiple layers of modern applications (i.e. mobile, REST APIs, SOAP services, Microservices, databases, Web UIs, ESBs, or mainframes) from a single intuitive interface.

  • Rapid and scriptless test creation: Automatically generate tests from a service definition to test design of an API. Use drag and drop tools for data driving, looping and performing complex assertions
  • Save time building tests: SOAtest plug-in leverages artificial intelligence to automatically convert UI tests into scriptless API test scenarios
  • Change management: SOAtest can identify service schema changes and automatically update your library of tests
  • Maximum scalability: Integration for existing SDLC test frameworks and CI infrastructures. Seamless integration with load testing and service virtualization
  • Robust and flexible integration: Broad support for 120+ protocols and message formats including JMS, MQ, TCP, File, Copybook, FIX, EDI and many more

2) API Fortress

API Fortress is the most powerful API testing and monitoring solution for REST and SOAP APIs.

  • Comprehensive test generation with a single click.
  • Web-based collaborative tool for teams. Works within your browser and requires no downloads.
  • Intuitive UI that is easy to use at any skill level.
  • Simple one-click automation. Test during development and deployments (CI/CD), and monitor functional uptime.
  • Robust notification and data integrations.
  • Works in the cloud, on-premises, or both in an ad hoc manner.

Hundreds of enterprises have already made the switch. More power, less confusion. The easiest way to automate your API testing and monitoring strategy.

3) Ping API

Ping-API is API testing allows to write test script in JavaScript and CoffeeScript to test your APIs. It allows inspecting HTTP API call with a complete request and response data. For any failures, the user gets a notification through email, slack or Hipchat.


  • Ping- API to schedule test in every minutes or hour
  • Support for writing script to set request headers, body and URL parameters. It supports for writing script to validate response headers and body
  • Validate CRUD flow and log in to Ping API

Download link: https://ping-api.com/


It provides an extensible framework helpful in executing and building the functionality of headless system that do not have a user interface. It helps to test the headless technologies like Databases and Webservices, JMS, etc. By using the API test conversion tool, you can convert soapUI tests to UFT (QTP) API tests.

Download QTP

5) vREST

vREST provides an online solution for automated testing, mocking, automated recording and specification of REST/HTTP APIs/RESTful APIs.

  • It provides an exhaustive tool to quickly validate your REST APIs
  • It delivers zero defect web applications with less effort in API testing
  • To validate your web application no skilled resources are required, and it can generate documentation for your API specifications
  • API mocks can be created in vREST with the help of Mock Server Functionality. User can directly start developing frontend using mock HTTP requests

Link to Vrest

6) Postman

Postman is a plugin in Google Chrome, and it can be used for testing API services. It is a powerful HTTP client to test web services. For manual or exploratory testing, Postman is a good choice for testing API.

  • With Postman, almost all modern web API data can be extracted
  • You can write Boolean tests within Postman Interface
  • You can create a collection of REST calls and save each call as part of a collection for execution in future
  • Unlike CURL, it is not a command line based tool, which makes this tool hassle free of pasting text into command line window
  • For transmitting and receiving REST information, Postman is more reliable

Link to Postman

7) HttpMaster

It is a web development tool to automate web application testing, including API testing, service testing and website testing. It is primarily used as web API test tool to automate testing of web API calls.

HttpMaster is a best choice for API testing as it has got

  • Several http methods (GET, POST, DELETE etc.)
  • Dynamic parameters of various data types to make batches of different API requests
  • Various validation types and advanced validation expressions

Download HttpMaster

8) Rest-assured

It’s a popular framework to test REST services in Java.

Learn more about Rest-Assured

Download HttpMaster

9) Karate DSL

Karate is a new API testing framework base on cucumber library. Karate DSL allows testers to write meaningful tests for web service using a domain-specific language.


  • It supports configuration switching/staging, multi-threaded parallel execution
  • Allows testing and generating reports just like any standard Java Project
  • Possible to write tests even for the non-programmers
  • The karate API testing tool allows re-use of payload-data and user-defined functions across tests.

Download link: https://github.com/intuit/karate

10) Rest Console

HTTP client and Request visualizer and constructor API testing tool. It helps developers to build, debug and test RESTful APIS.


  • Construct POST or PUT body via raw input
  • Easy query parameters creation
  • Add custom headers through intuitive UI
  • Keyboard navigation and shortcuts

Download link: https://github.com/ahmadnassri/restconsole

11) Hippie-Swagger

Hippie-swagger is a tool for testing APIS. It supports a clear assertion syntax, for extending test behavior. It also allows clean printing reports.


  • It will fail test whenever swagger documentation is either erroneous or missing
  • Readable and accurate assertation messages
  • Validated parameters, request, response, pats, etc.

Download link: https://github.com/CacheControl/hippie-swagger

12) Pyresttest

PyRestTest is a Python-based REST API testing platform. It supports tests in JSON or YAML config files. Therefore, there is no code needed.


  • It’s minimal dependencies, which allows easy deployment on-server for smoke tests/health checks
  • This API testing tool will return exit codes on failure
  • Pyresttest allows to generate/extract and validate mechanisms to build test scenarios

Download link: https://github.com/svanoort/pyresttest

13) Airborne

Airborne is an API automation testing tool used for testing Rest APIs.


  • Airborne is a programming framework, so it has no user interface apart from the text file to create code
  • To use airborne, you just need to remember a few key methods in the toolset and some ruby and rspec fundamentals

Download link: https://github.com/brooklynDev/airborne

14) JMeter

JMeter is used for functional API testing which includes needed to test an API. It also has features which help to boost the performance of API testing.


  • It can be used for both static as well as dynamic resources performance testing
  • It supports replaying of test results
  • It can automatically work with CSV files. This helps test team to produce unique parameter values for API tests

Download link: http://jmeter.apache.org/

15) APIpray Inspector

Apiary allows monitoring the API during the design phase by capturing both request and response. It allows the user to write API blueprints and lets the user view them Apiary editor or Apiary.jo.


  • Role-based access control over API documents.
  • It allows to add and remove team members from API design projects
  • API Blueprint management dashboard

Download link: https://apiary.io/

16) SOAP Sonar

SOAPSonar is an API testing and diagnostics platform for SOAP, XML, REST-based web services. Use external sources like Excel, MS SQL, Oracle or any ODBC Database for automated tests.


  • Identifies Web Services vulnerabilities like Malware Threat and SQL Injection
  • Web Service Functional Testing with Success Rule Framework and Concurrent Client Load Testing
  • Native HP QC Integration, and supports integration with Hudson, Ant, and JUnit

Download link: http://www.crosschecknet.com/

17) API Science

API science allows monitoring the health, availability, and performance of web APIs. The tool enables monitoring Private, Partner and Public APIs. This tool allows the user to know if any API ever goes down so that needed action should be taken to bring it back up.


  • It is multi-step & Powered by JavaScript
  • Powerful reporting mechanism helps to get insights into historical trends and spot future issues.
  • Supports JSON, REST, XML, and Oauth
  • Helps to manage API supply chain

Download link: https://www.apiscience.com/

18) Apigee

Apigee is a cross-cloud API testing tool. It allows the user to measure and test API performance, supports and build API using other editors like Swagger. It offers security and governance policies across all APIs.


  • Allows to design monitor, deploy, and scale APIs
  • Easily create API proxies from the Open API Specification and deploy them in the cloud
  • Identify performance issues by tracking API traffic, error rates, and response times

Download link: http://apigee.com/

19) Tricentis

Top 20 API Testing Tools

Tricentis is a robust web services testing tool. Prominent API Testing features of Tricentis Tosca are –

  • It supports a wide array of protocols including HTTP(s) JMS, AMQP, Rabbit MQ, TIBCO EMS, SOAP, REST, IBM MQ,NET TCP
  • It integrates into the Agile and DevOps Cycle
  • It uses model-based test automation that makes script maintenance easy.
  • Enables end-to-end testing as API tests can be used across mobile, cross-browser, packaged apps, etc.

Tricentis’ 400+ customers include global names from the Top 500 brands such as ExxonMobil, HBO, Whole Foods, Toyota, Allianz, BMW, Starbucks, Deutsche Bank, Lexmark, Orange, A&E, Vantiv, Vodafone, Telstra and UBS.

Download link: https://www.tricentis.com/automated-software-testing-tool-trial/


Top 20 API Testing Tools

The most widely popular tool for API testing in the world, SoapUI allows you to test REST and SOAP APIs with ease – as it has been built specifically for API testing.

  • Quick and Easy Test Creation: Point-and-click, drag-and-drop, functionality makes complicated tasks (like working with JSON and XML) simple
  • Powerful data-driven testing: Load data from Excel, files, and databases to simulate the way consumers interact with your APIs
  • Reusability of Scripts: Reuse your functional test cases as load tests and security scans in just a few clicks
  • Seamless Integrations: Integrates with 13 API management platforms, supports REST, SOAP, JMS, and IoT

SoapUI Pro is used by thousands of leading companies around the world, including: Apple, Microsoft, Cisco, Oracle, HP, NASA, eBay, MasterCard, Intel, FedEx, and Pfizer

Download link: https://smartbear.com/product/ready-api/soapui/overview/